1. Field of the Invention
The invention relates to a device for driving components of an escalator or a moving walkway.
2. Related Art
It is generally known that escalators or moving walkways are indirectly or directly driven by means of electric motors. In case of an indirect drive, at least one reducing gear is provided. In case of need, power dividers can be additionally provided in a region in which mobile components of escalators or moving walkways can be driven together. Such components are the step or pallet band, as well as the handrail, if required, and if a separate drive means is not provided for the respective one. Usually the step or pallet band is displaced by means of plate link chains, the moving direction of which is changed in the reversing areas via chain wheels provided in these areas. An essential requirement of escalators and moving walkways is to enable the reversing of the step or pallet band without the undesired polygon effects and to obtain a synchronous running of the step or pallet band and the handrail, when they are driven together, so that one component does not run at a higher or lower speed than the other, which could cause passenger injuries.
In view of an optimization of the drive concept, in particular for reducing the polygon effect generated in the reversing areas, plate link chains can be used for the step or pallet band, which chains also have a greater pitch depending on the step or pallet width, for example approximately 200 or approximately 400 mm. If required, a driving motor, which runs with a non-constant speed, can be in active relation therewith. However, it is possible that these desired greater chain pitches will cause problems with respect to the polygon effect during the reversing and possibly with respect to the synchronous drive of the handrail.